Process of preparing vulcanized fibers



Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE I ERNST BECKER, OF HAMBURG, GERMANY, ASSIGNOR TO I. G. FARBENINDUSTRIE- AKTIENGESELLSGHAET, OF FRANKFORfIP-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY PROCESS OF PREPARING VULGANIZED FIBERS No Drawing. Application filed May 29, 1929, Serial No. 367,135, and in Germany June 4, 1928.

addition of a soluble salt which is not decomposed by the sulfuric acid, for example, al-- kali metal sulfates, ammonium sulfate, and

' magnesium sulfate. These salts counteract the dispersing action of the sulfuric acid; the solution of the paper proceeds much more slowly, which enables the paper to be rolled into a fiber plate on the rollers. The action of the soluble salts, such as for example sulfates, increases with the valency of the base, apart from the quantity added. It is of particular value that the hydration or parchmentizing of the cellulose can in this manner be varied to a far reaching extent, that is to say vulcanized fibers and the like of homogeneous character and high specific gravity and likewise more fibrous, flexible fiber of low specific gravity can be manufactured as desired.

Furthermore, for the manufacture of vulcanized fibers, parchment paper and the like by the continuous process on the so-called 'parchmentizing machine an acid with the advulcanized fibers and the like, the step which comprises parchmentizing paper with sulfuric acid to which a sulfate soluble in sulfuric acid has been added. I

2. In the process for the manufacture of vulcanized fibers and the like the step which comprises parchmentizing paper with sulfuric acid to which 0.5 to 5% of a sulfate soluble in sulfuric acid has been added.

3. In the process for the manufacture of vulcanized fibers and the like the step which comprises parchmentizing paper with sulfuric acid to which ammonium sulfate has been added.

4. In the process for the manufactureof vulcanized fibers and the like the step which comprises parchmentizing paper with sulfuric acid to which 4 to 5% of ammonium sulfate has been added.

In testimony whereof I have hereunto set my hand.

ERNST BECKER.

ditions specified can be used with advantage,

"especially when it is desired to weaken the action of the sulfuric acid, for example, in

piliie case of certain wood pulp papers and the The invention is illustrated by some of the compositions of the baths in question, but is not limited thereto:

Example 1 .T he parchmentizing bath contains: 68% sulfuric acid -2% magnesium sulfate.

E wample 2.The parchmentizing bath contains: 70% sulfuric acid 45% ammonium sulfate. I claim: 1. In the process for the manufacture of 

